Throttle for gaseous fuels

ABSTRACT

An accelerator control system for an automobile employing a gaseous fuel in an internal combustion engine, characterized by a dome loaded pressure regulator interposed between a fuel reservoir and an intake manifold; and a fluid sealed signal conveying unit connected with the dome of the pressure regulator and responsive to movement of an accelerator pedal to transmit rapidly acceleration and deceleration signals to the pressure regulator and correspondingly increase or decrease the intake manifold pressure. The engine has a separate air intake manifold but its power; and, hence, r.p.m. at a given load condition; are controlled by the pressure regulator. Also disclosed are preferred embodiments which employ a shut-off valve intermediate the manifold and the fuel source, adjustable flow restrictions in conduits leading to the individual cylinders to obtain even fuel distribution, and trim pressure adjustment on the signal conveying unit for controlling the idling manifold pressure.

States Patent [l5] [451 an,

[72] Inventor:

[52] US. Cl ..l23/l20 [51] Int. Cl ..F02m 21/02 [58] Field oiSearch..l23/l20, 108,27 GE, 75 B, 123/106; 137/505.42

[56] References Cited UNITED STATES PATENTS 2,352,003 6/1944 Poinsignon123/120 X 2,896,599 7/1959 Ensign 123/120 3,306,273 2/1967 Dolphin123/120 X 2,972,988 2/1961 Ranck ..l23/l20 3,540,419 11/1970 Fox 123/120X 2,652,039 9/1953 Weslake... .....l23/75 B 2,320,886 6/1943 Quiroz......137/505.42 2,753,856 7/1956 Rush ..l23/l20 2,780,209 2/1957 Renken..123/120 X 3,357,687 12/1967 Vanderpoel. .....l23/120 X 2,724,372l1/1955 Schowalter ..l23/27 GE FOREIGN PATENTS OR APPLICATIONS 806,39712/1936 France 123/120 Primary Examiner-Mark M. Newman AssistantExaminer-Richard Rothman Attorney-Wofl'ord and Felsman [57] ABSTRACT Anaccelerator control system for an automobile employing a gaseous fuel inan internal combustion engine, characterized by a dome loaded pressureregulator interposed between a fuel reservoir and an intake manifold;and a fluid sealed signal conveying unit connected with the dome of thepressure regulator and responsive to movement of an accelerator pedal totransmit rapidly acceleration and deceleration signals to the pressureregulator and correspondingly increase or decrease the intake manifoldpressure. The engine has a separate air intake manifold but its power;and, hence, r.p.m. at a given load condition; are controlled by thepressure regulator. Also disclosed are preferred embodiments whichemploy a shut-off valve intermediate the manifold and the fuel source,adjustable flow restrictions in conduits leading to the individualcylinders to obtain even fuel distribution, and trim pressure adjustmenton the signal conveying unit for controlling the idling manifoldpressure.

6 Claims, 1 Drawing Figure TnaoTTLE FOR GASEOUS FUELS BACKGROUND OF THEINVENTION l. Field of the Invention This invention relates toimprovements in fuel supply apparatus for internal combustion engines.More particularly, it relates to an improved accelerator control systemfor an internal combustion engine employing a gaseous fuel.

2. Description of the Prior Art A wide variety of accelerator controlstructures and systems are known in the prior art for controllinginjection of fuel; or in effecting supplemental control in a fuel airmixture wherein fuel enrichment or derichment is effected in response tovacuum pressure detected via an intake manifold. Moreover, it is knownto control flow of air and fuel in response to a computer to effect anoptimum fuel air ratio in an engine being operated under fairly constantloads such as are encountered on a pipeline. Such prior art systems havenot been satisfactory in effecting operation of an internal combustionengine on a gaseous fuel such as natural gas in response to rapidacceleration and deceleration changes such as effected in an ordinarydriver driving an automobile in traffic. Moreover, the prior art systemshave controlled the fuel air ratio and have not effected satisfactorycombustion without controlling the influx of the air, or otheroxygen-containing gas for supporting combustion.

BRIEF DESCRIPTION OF THE DRAWING The FIG. is a schematic view, partly insection, illustrating one embodiment of this invention.

DESCRIPTION OF PREFERRED EMBODIMENTS It is an object of this inventionto provide an accelerator control system that is operable to controlpower; and, hence, revolutions per minute (r.p.m.); by controlling onlythe intake manifold pressure of a gaseous fuel in response to anaccelerator pedal means.

It is a specific object of one aspect of this invention to provide anaccelerator control system that employs a rapid conveyance, via apressure wave in a fluid medium, of acceleration and decelerationsignals to effect a corresponding and compensated response in thepressure of a gaseous fuel in a fuel intake manifold, regardless of thepressure of a fuel tank containing the gaseous fuel.

Referring to the figure, internal combustion engine 1 1 has a pluralityof cylinders 13 for internal combustion of a gaseous fuel to derivepower therefrom. As is conventionally employed, a piston, connectingrod, and crank shafts are employed within the internal combustion engine11 to convert the chemical energy into a useable mechanical form. Afiring means; such as, a glow plug or spark plug 15; is connected viasuitable conductor 17 with an electrical distribution system foreffecting timed ignition of a fuel charge within each cylinder 13. Theelectrical interconnection of conductors via an appropriate distributorand distribution system to efiect the timed ignition is well known, doesnot comprise a part of this invention and need not be described herein.

Internal combustion engine 11 also has an oxygen intake means such asair intake manifold 19. Air is drawn in through a suitable filter 21 toremove dust and other destructive particles therefrom. If a conventionalengine having a carburetor thereon is employed, it may be converted bysimply opening the butterfly valve in the throat of the carburetor. Itis not necessary to control the flow of air in this embodiment of thisinvention. The actual air intake into the cylinder may be effected viaintake valves or suitably located ports, depending upon whether internalcombustion engine 11 is a two cycle engine or a four cycle engine. Theintake porting or valving for either type of engine is well known andneed not be described herein.

Internal combustion engine 11 employs, as indicated, a gaseous fuel. Thegaseous fuel may be contained in a fuel tank 23 at super atmosphericpressure. For example, fuel tank 23 may contain natural gas at apressure of up to 2,200 pounds per square inch gauge (p.s.i.g.). Fueltank 23 may be connected by appropriate pressure conduit 25 with anintake manifold means at the internal combustion engine ill. If desired,a high pressure regulator 27 may be employed to control the pressure inpressure conduit 25 at some relatively high pressure higher than will bedesired in the fuel intake manifold means, but lower than the pressurein the fuel tank 23; for example, at a pressure in the range of about50-100 p.s.i.g.

The fuel intake manifold means may comprise a fuel intake manifold 29and a plurality of individual flow conduits 31. Each flow conduit 31 isconnected with the fuel intake manifold 29 and with a respective one ofthe cylinders 13. Each flow conduit 31 has interposed in it a checkvalve 33 and an adjustable flow restricting means such as restrictionvalve 35. Check valve 33 prevents backflow of high pressure fluid fromwithin cylinder 13 on the compression stroke of the piston therewithin.Individual restriction valves 35 are adjusted to obtain a uniformquantity of fuel through each respective individual flow conduit 31 intoeach respective cylinder 13 at a given pressure in the fuel intakemanifold 29. Thus, uniform power is developed in each respectivecylinder regardless of the pressure on fuel intake manifold 29.Preferably, the actual injection passageway 37 and check valve 33 areclosely adjacent the internal chamber of cylinder 13 with injectionpassageway 37 canted so as to deliver a charge of gaseous fuel that, incombination with the entering air, effects a swirling movement so thatthe fuel is directed toward the center of the cylinder 13. In this way,the richest portion of the fuel air mixture will occur adjacent sparkplug 15 so as to always effect ignition of the fuel regardless of howlean the fuel air mixture becomes adjacent the peripheral wall of thecylinder 13.

A fuel cut-off valve that is operable into an open and into a closedposition for running and stopping the internal combustion engine 11 isinterposed between and in series connection with fuel intake manifold 29and fuel tank 23. Specifically, solenoid actuated valve 39 is interposedin conduit 41 so as to be electrically operable into an open positionfor starting the engine and into a closed position for stopping theengine. Its associated solenoid 43 may be a self-latching relay suchthat when pulsed, as by turning an ignition key on or off, it isenergized electrically or mechanically into and remains in acorresponding position until oppositely pulsed; or, it may be maintainedenergized all the time the ignition key is on to maintain the valve 39open. While cut-off valve 39 may be interposed at any locationintermediate fuel tank 23 and fuel intake manifold 29, it is preferablylocated downstream of fuel pressure regulator 45 so that a low pressurevalve may be employed.

The fuel pressure regulator 45 is interposed in series connection withcut-off valve 39 between fuel intake manifold 29 and fuel tank 23. Thefuel pressure regulator 45 is operable to control a downstream pressurethat is substantially the same as the pressure in the fuel intakemanifold. Normally, the pressure in the fuel intake manifold runs froman idling pressure of only a few inches of water to a maximum runningpressure of several or even many p.s.i.g. Preferably, the pressureregulator 45 has a biasing element such as spring 47 and a pressureresponsive element such as diaphram 49. Spring 47 is preset to effect apredetermined downstream pressure at atmospheric pressure on diaphram49. The compressive force on spring 47 may be effected by a suitablescrew passed through a threaded aperture. The screw is thus pre-set atthe factory, although it may be altered by removing a portion of thedome and; for example, screwing inwardly to increase the pressure. Asillustrated, however, dome 51 is dome loaded. That is, it is sealinglyconnected with diaphram 49 and not vented to the atmosphere. Thus, thedome pressure acting on diaphram 49 may be altered to increase ordecrease the downstream pressure. Fuel pressure regulator 45 may be ofthe single stage compensated type such as described in copendingapplication Ser. No. 827,711, by Ray R. Zimmer entitled Single Stage,

Compensated Pressure Regulator, and assigned to the assignee of thepresent invention, or it may be a two stage compensated regulator. Thecompensation is preferably employed to obtain accurate and predictableresponse in effecting a desired manifold pressure regardless of thepressure in fuel tank 23. Such compensation becomes less critical if ahigh pressure regulator 27 is employed although it is still desirable ifthe fuel pressure in fuel tank 23 becomes less than the pressure forwhich the high pressure regulator 27 is set.

An accelerator pedal means is disposed in the interior of the automobilefor imparting relatively rapid acceleration and deceleration signals tothe internal combustion engine 11.

' Specifically, a foot accelerator pedal 53 is pivotally mounted onmounting 55. Foot accelerator pedal 53 is depressed to signal anacceleration signal and is allowed to spring upwardly to signal adeceleration signal to the fuel pressure regulator 45. Fuel pressureregulator 45, in turn, controls the pressure in the fuel intake manifold29 and, consequently, the power output from the internal combustionengine 11.

A fluid sealed signal conveying means is disposed intermediate theaccelerator pedal means and the fuel pressure regulator for signalingthe fuel pressure regulator to increase or decrease the fuel intakemanifold pressure in response to the respective acceleration ordeceleration signal from the accelerator pedal means. The fluid sealedsignal conveying means 57 comprises a conduit means 59 and a pressuregenerating unit 61. The conduit means 59 is connected with dome 51 ofthe fuel pressure regulator 45 so as to alter the manifold pressure as apredetermined function of the pressure in the signal conveying means 57.The pressure generating unit 61 is connected with the other end of theconduit means and positioned adjacent and operably responsive to theaccelerator pedal means illustrated as foot accelerator pedal 53. Asillustrated, dome 51 is sealingly connected with the conduit means 59such that any pressure generated by pressure generating unit 61 istransmitted directly to diaphram 49 and a predetermined andcorresponding change in downstream pressure thereby effected. Thus, anacceleration signal, denoted by depression of foot accelerator pedal 53,is conducted with the speed of the pressure wave via conduit means 59 todiaphram 47 to signal the fuel pressure regulator 45 to increase thedownstream pressure, or fuel intake manifold pressure, Conversely,releasing foot accelerator pedal 53 signals a decrease in fuel intakemanifold pressure via the same route.

The pressure generating unit 61 has a centrally disposed diaphram member63 that is disposed adjacent and responsive to shaft 65, which is, inturn, responsive to movement of foot accelerator pedal 53. Shaft 65 maybe connected with diaphram member 63 as by a nut; and with footaccelerator pedal 53 as by a pivot pin; or otherwise held as by beingcompressively disposed therebetween. Spring 67 beneath diaphram member63 biases diaphram member in the opposite direction to decrease thepressure in the pressure generating unit 61 when the foot acceleratorpedal 53 is released. Expressed otherwise, diaphram member 63 isdepressed to increase the pressure by downward movement of acceleratorpedal 53 and is moved in the opposite direction of decrease the pressurein the dome 51 by the spring 67.

The signal conveying unit may be filled with either a gas or a liquid. Agas such as air affords a convenience in loading and is economical. Onthe other hand, a liquid has less compressibility and effects a morerapid response to the acceleration or deceleration signals.

A trim pressure adjustment means is provided for effecting apredetermined pressure in the dome 51 at a given setting of theaccelerator pedal for controlling the manifold pressure at the idlingspeed of the engine. Specifically, a screw 69 is sealingly inserted in athreaded aperture 71 in pressure generating unit 61 such that thediaphram member 63 may be positioned at any point to effect a givenquantity of the fluid in the signal conveying means 57. Screw 69 isthereafter inserted to trap the fluid therein and effect thepredetermined pressure. in addition, the pressure may be adjustedprecisely by increasing or decreasing the volume minutely, as byscrewing screw 69, respectively, outwardly or inwardly.

In operation, a given quantity of fluid is entrapped in signal conveyingmeans 57 and the foot accelerator pedal 53 allowed to rest at a desiredposition. Once set, little further adjustment need be made. The ignitionkey may be turned on to open solenoid valve 39 and connect the fuelintake manifold 29 with the fuel pressure regulator 45 for starting theengine. The engine is started in the conventional manner. Upon a signalto accelerate, fuel pressure regulator 45 increases the pressure in thefuel intake manifold 29 from a few inches of water to several p.s.i.g.,depending upon the degree of acceleration signalled by the driver.

Within the individual cylinders, air is taken in at a relativelyconstant rate if there is no adjustable butterfly or obstruction. On theintake, when the pressure in the cylinder gets below the pressure in thefuel intake manifold, the gaseous fuel flows through check valve 33 andthrough canted passageway 37 into the interior of cylinder 13. Ifinternal combustion engine 11 is a two cycle engine this fuel flowoccurs on every stroke. Alternatively, if it is a four cycle engine thefuel flow may occur on every stroke if desired to sweep out the exhaustgases; or it may be valved such that the fuel gas is taken into thecylinder only on the compression stroke. In any event, the gaseous fuelis admixed with the air; although not necessarily uniformly, since it ispreferably richer in the central portion adjacent the spark plug, or theglow plug. At the proper time, as determined by a distributor, the fuelis ignited and burned in cylinder 13 for delivering power during theexpansion stroke. if it is desired to decelerate, the foot is removedfrom the foot accelerator pedal and the diaphram member 63 movesbackwardly, or upwardly, decreasing the pressure in dome 51 and ondiaphram 49. This effects a decreased downstream pressure and adecreased pressure in the fuel intake manifold 29. Consequently, lessfuel is delivered to the cylinder 13 and lower power is realized fromthe engine. There is a concomitant slowing of the automobile. lfacceleration is again signalled by depression of the foot acceleratorpedal, diaphram 49 senses the increased pressure and increases the fuelpressure in the fuel intake manifold 29. Consequently, a greater amountof fuel enters the cylinder 13 to deliver a greater amount of power.

When it is desired to kill the engine, cut-off valve 39 is closed to cutoff the flow of fuel thereto.

A preferred embodiment has been described hereinbefore in which a fluidfilled signal conveying means is employed intermediate a footaccelerator pedal and a fuel pressure regulator for controlling thepressure of the fuel in a fuel intake manifold. If desired, otherembodiments, such as, a mechanical connection between the footaccelerator pedal and a spring balanced diaphram in the fuel pressureregulator; could be employed to control the fuel pressure in the fuelintake manifold. Such embodiments may have, however, aspects that arenot as advantageous as the preferred embodiment described hereinbefore.

One of the advantages of this invention is that no exotic new materialsare required but those materials ordinarily employed in manufacturingpressure regulating elements, valves and engine parts, may be employedherein. One advantage that has been found with this operation, in whichthe richest fuel air mixture is adjacent the glow plug 15, is that, ifdesired, the electrical charge to the glow plug 15 can be reduced afterthe engine has been warmed up and still effect satisfactory combustion.

It can be seen from the foregoing descriptive matter that this inventionprovides an accelerator control system that obviates the disadvantagesof the prior art devices and controls the power; and, hence, rpm at agiven load; by controlling only the intake manifold pressure for agaseous fuel in response to an accelerator pedal operation. It also canbe seen that this invention provides an accelerator control system thatemploys a fast response in one aspect, via a pressure wave in a confinedfluid medium, to convey the acceleration and deceleration signals to apressure regulator that correspondingly and responsively controlspressure of a fuel intake manifold to regulate the power provided by aninternal combustion engine.

Although the invention has been described with a certain degree ofparticularity, it is understood that the present disclosure is made onlyby way of example and that numerous changes in the details ofconstruction and the combination and arrangement of parts may beresorted to without departing from the spirit and the scope of theinvention.

What is claimed is:

1. An accelerator control system for an automobile employing a gaseousfuel in the cylinders of its internal combustion engine, comprising:

a. oxygen intake means connected with said cylinders for intake of acombustionsupporting gas; said oxygen intake means being set at apredetermined setting independent of movement of an accelerator pedalmeans in a gas flow system controlling the flow of the gaseous fuel;

. a source of gaseous fuel at super atmospheric pressure;

c. fuel intake manifold means comprising a fuel manifold connected withsaid source of gaseous fuel, and a plurality of flow conduits; each flowconduit being connected with said manifold and with a respective one ofsaid cylinders and having a check valve means connected therewith forpreventing back flow of fluid from said cylinder to said fuel manifold;

d. a fuel cut-off valve that is operable into an open and into a closedposition for running and for stopping said engine;

e. a fuel pressure regulator that is operable to control a downstreampressure that is substantially the same as the pressure in said manifoldfrom an idling pressure of a few inches of water to a maximum runningpressure of many pounds per square inch gauge in response to a biasingelement and a pressure responsive element associated therewith; saidflow pressure regulator and said fuel cutoff valve being interposed inseries connection between and connected with said source of gaseous fueland said fuel intake manifold means;

accelerator pedal means disposed in the interior of said automobile forimparting relatively rapid acceleration and deceleration signals to saidfuel pressure regulator; and g. fluid sealed signal conveying meansdisposed intermediate said accelerator pedal means and said fuelpressure regulator for signalling said fuel pressure regulator toincrease or decrease the fuel manifold pressure in response respectivelyto the accelerate or decelerate signal from said accelerator pedalmeans; said fluid sealed signal conveying means comprising a conduitmeans connected at one end with said fuel pressure regulator so as toalter the manifold pressure as a predetermined function of the pressurein said signal conveying means; and a pressure generating unit sealinglyconnected with the other end of said conduit means and positionedadjacent and operably responsive to said accelerator pedal means.

2. The accelerator control system of claim 1 wherein said fuel pressureregulator is a compensated, preset, dome loaded pressure regulator, thedome of which is sealingly connected with said conduit means of saidsignal conveyor means, said dome being also sealingly connected with adiaphram serving as said pressure responsive element of said fuelpressure regulator.

3. The accelerator control system of claim I wherein said flow conduitscontain respective adjustable flow restricting means for effecting equalflow of the gaseous fuel to all cylinders.

4. The accelerator control system of claim 1 wherein said signalconveying means contains a trim pressure adjustment means for effectinga predetermined pressure therein for controlling the manifold pressureand, consequently, the speed of said engine when idling.

5. An accelerator control system for an automobile employing a gaseousfuel in the cylinders of its internal combustion engine, comprising:

a. oxygen intake means connected with said cylinders for intake of acombustionsupporting gas; said oxygen intake means being set at apredetermined setting independent of movement of an accelerator pedalmeans in a gas flow system controlling the flow of the gaseous fuel;

b. a source of gaseous fuel at super atmospheric pressure;

0. fuel intake manifold means comprising a fuel manifold connected withsaid source of gaseous fuel, and a plurality of flow conduits; each flowconduit being connected with said manifold and with a respective one ofsaid cylinders;

. a fuel cut-off valve that is operable into an open and into a closedposition for running and stopping said engine;

e. a fuel pressure regulator that is operable to control a downstreampressure that is substantially the same as the pressure in said manifoldfrom an idling pressure of a few inches of water to a maximum runningpressure of many pounds per square inch gauge; said flow pressureregulator and said fuel cut-off valve being interposed in seriesconnection between and connected with said source of gaseous fuel andsaid fuel intake manifold means;

f. accelerator pedal means disposed in the interior of said automobilefor imparting acceleration and deceleration signals to said fuelpressure regulator; and

g. signal conveying means disposed intermediate said accelerator pedalmeans and said fuel pressure regulator for signalling said fuel pressureregulator to increase or decrease the fuel manifold pressure in responserespectively to the accelerate or decelerate signal from saidaccelerator pedal means; said signal conveying means being connectedwith said fuel pressure regulator so as to alter the manifold pressureas a predetermined function of movement of said accelerator pedal means.

6. The accelerator control system of claim 5 wherein a high pressureregulator is emplaced intermediate said source of gaseous fuel and saidfuel pressure regulator to control the pressure therebetween at apressure intermediate the super atmospheric pressure of said source ofgaseous fuel and the fuel manifold pressure; and wherein a check valvemeans is interposed between each said respective cylinder and each saidflow conduit in association with a canted injection passageway whichinjects the gaseous fuel into said cylinder at an angle so as to effecta swirling motion within said cylinder and emplace the richest part ofthe fuel air mixture adjacent a firing means in said cylinder.

i i X i lnunn A.

1. An accelerator control system for an automobile employing a gaseousfuel in the cylinders of its internal combustion engine, comprising: a.oxygen intake means connected with said cylinders for intake of acombustion-supporting gas; said oxygen intake means being set at apredetermined setting independent of movement of an accelerator pedalmeans in a gas flow system controlling the flow of the gaseous fuel; b.a source of gaseous fuel at super atmospheric pressure; c. fuel intakemanifold means comprising a fuel manifold connected with said source ofgaseous fuel, and a plurality of flow conduits; each flow conduit beingconnected with said manifold and with a respective one of said cylindersand having a check valve means connected Therewith for preventing backflow of fluid from said cylinder to said fuel manifold; d. a fuelcut-off valve that is operable into an open and into a closed positionfor running and for stopping said engine; e. a fuel pressure regulatorthat is operable to control a downstream pressure that is substantiallythe same as the pressure in said manifold from an idling pressure of afew inches of water to a maximum running pressure of many pounds persquare inch gauge in response to a biasing element and a pressureresponsive element associated therewith; said flow pressure regulatorand said fuel cut-off valve being interposed in series connectionbetween and connected with said source of gaseous fuel and said fuelintake manifold means; f. accelerator pedal means disposed in theinterior of said automobile for imparting relatively rapid accelerationand deceleration signals to said fuel pressure regulator; and g. fluidsealed signal conveying means disposed intermediate said acceleratorpedal means and said fuel pressure regulator for signalling said fuelpressure regulator to increase or decrease the fuel manifold pressure inresponse respectively to the accelerate or decelerate signal from saidaccelerator pedal means; said fluid sealed signal conveying meanscomprising a conduit means connected at one end with said fuel pressureregulator so as to alter the manifold pressure as a predeterminedfunction of the pressure in said signal conveying means; and a pressuregenerating unit sealingly connected with the other end of said conduitmeans and positioned adjacent and operably responsive to saidaccelerator pedal means.
 2. The accelerator control system of claim lwherein said fuel pressure regulator is a compensated, preset, domeloaded pressure regulator, the dome of which is sealingly connected withsaid conduit means of said signal conveyor means, said dome being alsosealingly connected with a diaphram serving as said pressure responsiveelement of said fuel pressure regulator.
 3. The accelerator controlsystem of claim 1 wherein said flow conduits contain respectiveadjustable flow restricting means for effecting equal flow of thegaseous fuel to all cylinders.
 4. The accelerator control system ofclaim 1 wherein said signal conveying means contains a trim pressureadjustment means for effecting a predetermined pressure therein forcontrolling the manifold pressure and, consequently, the speed of saidengine when idling.
 5. An accelerator control system for an automobileemploying a gaseous fuel in the cylinders of its internal combustionengine, comprising: a. oxygen intake means connected with said cylindersfor intake of a combustion-supporting gas; said oxygen intake meansbeing set at a predetermined setting independent of movement of anaccelerator pedal means in a gas flow system controlling the flow of thegaseous fuel; b. a source of gaseous fuel at super atmospheric pressure;c. fuel intake manifold means comprising a fuel manifold connected withsaid source of gaseous fuel, and a plurality of flow conduits; each flowconduit being connected with said manifold and with a respective one ofsaid cylinders; d. a fuel cut-off valve that is operable into an openand into a closed position for running and stopping said engine; e. afuel pressure regulator that is operable to control a downstreampressure that is substantially the same as the pressure in said manifoldfrom an idling pressure of a few inches of water to a maximum runningpressure of many pounds per square inch gauge; said flow pressureregulator and said fuel cut-off valve being interposed in seriesconnection between and connected with said source of gaseous fuel andsaid fuel intake manifold means; f. accelerator pedal means disposed inthe interior of said automobile for imparting acceleration anddeceleration signals to said fuel pressure regulator; and g. signalconveying means disposed intermediate said accelerator pedal mEans andsaid fuel pressure regulator for signalling said fuel pressure regulatorto increase or decrease the fuel manifold pressure in responserespectively to the accelerate or decelerate signal from saidaccelerator pedal means; said signal conveying means being connectedwith said fuel pressure regulator so as to alter the manifold pressureas a predetermined function of movement of said accelerator pedal means.6. The accelerator control system of claim 5 wherein a high pressureregulator is emplaced intermediate said source of gaseous fuel and saidfuel pressure regulator to control the pressure therebetween at apressure intermediate the super atmospheric pressure of said source ofgaseous fuel and the fuel manifold pressure; and wherein a check valvemeans is interposed between each said respective cylinder and each saidflow conduit in association with a canted injection passageway whichinjects the gaseous fuel into said cylinder at an angle so as to effecta swirling motion within said cylinder and emplace the richest part ofthe fuel air mixture adjacent a firing means in said cylinder.